Fountain pen



April 9, 1935. w. A. sHEAFl-'ER Re. 19,530

= l FOUNTAIN PEN y original Filed March A12, 19:54

I| l WKK n www Reissued Apr.- 9, 1935 1 l i i I UNITED STATES PATENT OFFICE" Walter A. Sheafl'er, Fort Madison, Iowa, assignor to W. A. Sheaffer Pen Company, Fort Madison, Iowa, a corporation of Delaware v 8 Claims. (Cl. 1Z0-457) This invention relates to a fountail. pen and unaffected by the chemicalsof the writing fluid. has special reference to a. fountain pen employing In clamping the rubber disk between the backing a plunger movable longitudinally in the writing plate and clamping member, the compressibility fluid-containing barrel thereof to control the i111- of the rubber' can not be readily controlled and ing and evacuation of the barrel. the diameter of the disk itself may vary aside from 5 More particularly, this invention relates to that the variances already described in connection class of fountain pens in which ink or air conwith the expansion and contraction of the barrel. tained within the barrel is displaced from one Thus, the provision of an arcuate cross section side to the other of a plunger therein during the of the disk permits of variances in the diameter l0 stroke of the plunger away from the pen nib, and of the disk caused by the compressibility of the 10 v a partial vacuum is established in the barrel and rubber and such variances as are caused by the the ink'or airis expelled therefrom during the expansionA and contraction of the material of the stroke of the plunger toward the pen nib, the barrel itself. barrel being substantially lled with ink drawn One of the objects of this invention is to proln thereinto by the partial vacuum when the plungvide a fountain pen ofthe character noted above er reaches an enlarged bore at its limit of move' in which a normallyflat disk is held between a ment toward the pen nib during a single movebacking member and clamping member, the ment thereof. clamping member holding the disk in conform- In the present construction, a, plunger is emity to a concave surface of the backing memployed comprising preferably a normally flat disk ber to allow for variances in the diameter of the 20 provided between abacking member having a condisk and in the bore of the barrel of the pen. cave face and a clamping member,'the clamping Anotherobject of this invention is to provide a' member holding the disk inra conforming engageplunger for a fountain penof the .above noted ment with the concave surface. In this manner -type in which a normally ilat disk having va :fiat of construction, when the plunger is moved longiperipheral edge in .held in an arcuate cross sectudinally in one direction, the flow of ink is dtion to present a sharp edge for engagement rected around the plunger While the disk is in a With the bore of the barrel in either direction normal condition to direct such passage with a of travel of the plunger to minimize the fricminimum danger of obstructing the passage of tional engagement therebetween and permit an the ink of the barrel to the feed section. Further, easy movement of the plunger rod. 30

the disk is provided with alat peripheral edge A further object of this invention is to prowhich, when deformed into an arcuate cross secvide a fountain pen of the above noted type tion by being clamped between the concave surwhich is simple in construction and operation, face of the backing plate and the clamping memcomparatively inexpensive to manufacture and ber, presents a sharp edge for engagement with durable. 35

the wall of the barrel -in either direction of the Other objects and advantages will hereintravel of the plunger to minimize the frictional after be more particularly pointed out and for a engagement therebetween and permit an easy more complete understanding of the charactermovement of the plunger rod, although providing istic features of this invention, reference may o for at least the same eflicient substantially airlnowl behad to the following description when 40 tight engagement asmay be had in any other taken together with the accompanying drawing, condition. in which latter: v

The arcuate cross section ofthe plunger disk Figure 1 is a longitudinal sectional view of a Iurtherallows for variances in the diameter of fountain Den eInbOdying this invention With the l5 the bore of the barrel ofthe pen due to any conplunger ShOWn at the limit 0f movementthere- 45 traction and expansion of the material of..which 0f inward the pen nib; r the barrel is made. Ordinarily, the barrel is Fig. 2 is an enlarged fragmental sectional made of a plastic materialwhich is subject to View of a portion of the pen barrel with the temperature changes and the curvature thus ob-` plunger in the position therein shown in Figtained in the disk permits of a desired frictional ure 1;

engagement therebetween even though the diam- Fig. 3 is a view similar to Fig. 2,y showing a eter of the bore of the barrel may vary within the changed position of the plunger as the plunger expansible and contractible limits of the material. `diskis moved in a direction away from the pen The plunger diskis of a yielding' resilient matenib; and v v rial preferably of rubber which is substantially Fig. 4 is a view similar to Fig'. 3, showing the 55 'condition of the plunger disk during the movement of the plunger rod in a direction toward the pen nib. Y

Referring now more particularly to the drawing, this invention is shown as being embodied in an open-ended pen barrel III preferably of a plastic composition `material having a hollow cylindrical interior` or bore I. A peripheral portion of the barrel III is reduced at one end to engage the' b'ore of a pen section I2, that portion of the bore extending beyond the 4end of the barrel I0 forming an enlargement I3. The pen lsection I2 is provided in the usual manner with a feed bar I4 having the usual ink feeding passages for conducting ink to a pen nib I5, the feed bar |4 communicating with the enlargement I3 of the feed section. yThe exposed ink feeding mechanism and pen nib may be suitably enclosed with a cap I6 having threaded engage. ment with the pen section and having an inner I hard rubber sealing member I1 for engagement n with the end of the pen section.

A peripheral portion of the other end of the pen barrel I0 is reduced to engage the bore of a sleeve I8 formed preferably of a plastic composition material, the extending portion of the sleeve havingv internal threads I9 for engaging the external threads of a barrel plug 2|). The barrel plug 20, in turn, has a reduced threaded extension 2| for receiving an internally threaded cup-,shaped cap 22.

A plunger rod 23 preferably of Monel metal is provided with a sleeve 24 substantially throughout its length, one end of the rod having 'a preferably brass plunger button 25 to be grasped by the fingers in manipulating the rod and the other end being provided with a reduced threaded extension 26. The sleeve 24 covering the plunger rod 23 is formed preferably of rubber since such material is substantially not affected by the chemicals of the writing fluid, the

sleeve and rod being supported by the plug 20,

longitudinally of the barrel of the fountain pen,

the barrel plug 20 is provided with an internal aperture 21 of substantial depthfor receiving a series of apertured disks, the outer peripheries of the disks fitting snugly in the aperture 21 and the disks being apertured to snugly receive the hard rubber sleeve 24 of the plunger rod 23. It has been found in order to provide a substantially air-tight joint and yet permit the plunger to slide smoothly, that a plurality. of alternate rubber and felt disks be employed, the felt disks providing a desired amount of give on each side of the rubber disks. The provision of alternate rubber and felt disks has been found to be infinitely superior to the usual solid packing for the purpose of the present construction, that is, to provide ease of operation and yetobtain eiiicient and desired results.

'Ihe plug 2|) isy threaded into the sleeve I3 against a soft rubber gasket 28, which latter is disposed adjacent a disk 21| preferably of a plastice or other comparatively hard material such as that of the barrel itself, the latter disk abutting against the end of the barrel within the sleeve. Thus, a substantially air-tight joint is had to prevent-the escape orentrance of air through the threads of the barrel plug or between the plunger rod and the disks. f

A backing plate 30 is provided with a central aperture for receiving the reduced threaded end portion 26 of the plunger rod 23, one face of the plate abutting against a shoulder formed by the reduced end portion 26 and the other face being concave for engaging one side of a disk 3|. The disk 3| is provided with a central aperture for receiving a reduced extension 32 of a clamping member 33, the latter having an internally' threaded aperture to engage the threaded extension 26 for holding the disk 3| in conformingy engagement with the concave surface of the back ing plate 3II. The backing plate 30 and the clamping member 33 are formed preferably oiv hard rubber and the disk 3| is formed of a yielding resilient material preferably of soft rubber.

The plunger disk 3| is normally flat and has aperipheral' side formed at substantially right angles to the flat surfaces thereof. The backing plate, clamping member and interposed disk are of such diameters that a movement of the plunger in either direction longitudinally of the bore of the barrel II) will cause a rearward inclination of the disk 3| relative to the direction of movement thereof and will present the sharp edges between the flat faces and side of the disk alternately for engagement with the bore, as is shown more particularly in Figs. 3 and 4. In Fig. 3, the movement of the plunger is indicated by the arrow and a normal position of the plunger is shown in full lines, the sharp edge of the disk engaging the bore -II of the barrel I0. In dotted lines, aY spaced relation of the disk of the bore of the barrel is shown to indicate the relation of the disk in the barrel as ink and air are displaced from one side to the other of the plunger during the stroke of the plunger -away from the pen nib or in the direction of the arrow. In Fig. 4, the other sharp edge of the disk is shown as being presented to the bore II of the barrel whereby a partial vacuum is being created behind the plunger and the contents of the barrel in front of the plunger is being evacuated as the plunger is moved longitudinallyin the barrel until it reaches its limit of movement as shown in Fig. 2, where the filling of the barrel is accomplished by means of the breaking of the vacuum created behind the plunger.

In practical use and in assuming that there is a small quantity of ink within the Abore of the barrel I0 and it is desired to refill, the operator rst removes the cap 22 and grasps the plunger button 25 to move the same in a direction away from the pen nib. During this movement, the air and ink contained within the barrel will press upon,the plunger disk 3| suiciently to cause it to assume the position shown in dotted lines in Fig. 3 and air and ink may pass around the periphery of the disk 3| and occupy a position in the barrel on the opposite side of the plunger.

As soon las the plunger disk'has reached its limit of movement in a direction away from the pen, the disk, because of its resiliency, will assume a position with one of the sharp edges between a fiat peripheral side and a flat face of the disk held firmly in engagement with the bore of the barrel. When the plunger is moved in a direction toward the pen nib as shown in Fig. 4, the other sharp edge between the flat peripheral side and the other flat face of the disk will beurged tightly against the bore of the barrel so that air or ink will be expelled from the barrel in front will be created within the barrel at the rear of the plunger.

When the plunger disk 3| reaches the enlarged bore i3 of the pen section VI2 and assuming that the pen nib is inserted in a supply ofink, the ink will be drawn into the barrel I through the feed section I4 to approximately fill the barrel. Thus, the complete operation of expelling the contents of the barrel andthe filling of the barrel with ink is done with a single stroke of the plunger in one direction.

'Ihe diameter of the backing plate 3Uand the` clamping member 33 is smaller than the diameter l of the disk 3|, the diameter of the clamping member being, in turn, smaller than the backing plate. It is to be noted thata comparatively small peripheral portionof the disk is subjected to flexing.

While but a single embodiment. of this ,invention is herein shown and described, itis to be understood that various modifications thereof may be apparent to those skilled in the art'with'- out departing from the spirit and scope of this invention and, therefore, the same is onlyto be limited by the sco of the prior art and the appended claims.

I claim: l

1. A fountain pen of the character described including a barrel in which the bore at the writing point end thereof is provided with means to break the vacuum created behind a plunger in its movement thereto for filling the barrel' with a writing fluid, thel plunger being mounted on a rod for reciprocation in the barrel andcomprising a disk formed of yielding resilient material, a backing plate on said rod having a concave face for engaging one side of said disk, and a clamping member of substantially smaller diameter than said disk for holding said disk in conforming engagement with said concave face and for permitting the periphery of said disk to stand spaced apart from the bore when the plunger rod is moved awayfrom the writing point end, said backing plate being substantially rigid and extending over a substantial portion of said disk to provide a` fulcrum for the fiexure of said disk at a peripheral portion thereof when said lrod is moved in a direction toward the writing point end to effect a maximum ease of movement while maintaining a substantially air-tight engagement of said disk with the bore of said barrel.

2. A fountain pen of the character described including a barrel in which the bore at the writing point end thereof is provided with means to break the vacuum created behind a plunger in its movement thereto for lling the barrel witha writing uid, the plunger being mounted on a -rod for reciprocation in th barrel and comprising a normally fiat disk formed of yielding resilient material, a backing plate on said rod having a concave face for engaging one side of said disk, and a clamping member of substantially smaller diameter than said disk for holding said disk in conforming engagement with said concave face and for permitting the periphery of said disk to stand spaced apart from the bore when the plunger rod is moved away from the writing point end, said disk having a peripheral side formed at substantially right angles to the yfiat surfaces of said disk and said backing plate being substantially rigid and extending over a substantial portion of said disk tof-provide flexure of said disk at a peripheral portion thereat to present.

an edge of said disk between the face and side ,for engagement with the bore of said barrel when said rod is moved in a direction toward the writing point end to effect a maximum ease of movement of the plunger while maintaining a substantially air-tight engagement with the bore of the barrel.

3. A fountain pen of the character described including 'a barrel in which the bore at thewriting point end thereof is provided with means to break the vacuum created behind a plunger in its movement thereto for filling the barrel with a writing fluid, the plunger being mounted on a rod for reciprocation in the barrel and comprising a soft rubber disk of greater diameter lthan the bore of said barrel, a backing plate on said rod formed of hard rubber andhaving a concave face for engaging -one side of said disk, and a` hard rubber clamping member ofl substantially smaller diameter than said disk for holdingsaid.

disk in conforming engagement with said concave vface and for 'permitting the periphery of saiddisk to stand spaced apart from the bore when the plunger rod is moved away from the Writing point end, the concave face of said backing plate terminating short of the periphery of said disk and presenting `.thereat a fulcrum for the ilexure of said disk when said rod is moved in a direction toward the writing point endto effect a maximum ease of movement while maintaining a substantially air-tight engagement of said disk with said bore. A

4. A fountain pen of the character described including a barrel in which the bore at the writing point end thereof is provided with means to break the vacuum created behind a plunger in its movement thereto for filling the barrel with a Writing fluid, the plunger being mountedon a rod ffor reciprocation in the barrel and comprising a soft rubber disk of greater diameter than the bore of said barrel and having a central aperture, a backing plate on said rod formed of hard rubber and having a concave face for engaging one side of said disk, and a'hard rubber clamping member of substantially smaller diameter than said disk for holding `said disk in conforming engagement with said con'cave face'and for permitting the periphery of said disk to st and spaced apart from the bore when the plunger rod is moved away from the writing point end, said fulcrum for the fiexure of said 'disk when said l rod is .moved in a direction toward the writing point end to effect a. maximum ease of movement while maintaining a substantially air-tight engagement of said disk with said bore.

5.'A fountain pen of the character described including a barrel in which the bor'e at the writing point end thereof is provided with means to break the vacuum created behind a plunger in its movement thereto for lling the barrel with a Writing fluid, the plunger being mounted on a rod for reciprocation in the barrel and comprising a disk of yielding resilient material, a backingplate on said rod having a face for engaging one side of said disk, a separate clamping member of sub- Y from the bore when the plunger rod is moved away from the writing point end, said backing crum for the flexure of the outer portion of said disk on a substantial radius when said rod is moved in a direction toward the writing point end to eect a maximum ease of movement while maintaining a substantially air-tight engagement with the bore of the barrel. v

' 6. A fountain pen of the character described including a barrel in which the bore at the writing point end thereof is provided with means to break the vacuum created behind a plunger in its movement thereto for filling the barrel with a writing fluid, the plunger being mounted on a rod for reciprocation in thebarrel and comprising a disk of yielding resilient material, a backing plate on said rod having a face for engaging and supporting one side of said disk, and a clamping member of substantially smaller diameter than said disk for holding said disk in conforming engagement with said face of said backing plate and for permitting the periphery of said disk'to stand spaced apart from the bore when the plunger rod is moved away from the writing point end, said disk having a peripheral side formed at substantially right angles to the fiat surfaces of said disk and said backing plate being substantially rigid to extend over a substantial portion of said side of said disk and permitting a flexure of said disk at the peripheral portion thereof to present anredge of said disk between a face and side for engagement with ther bore of said barrel when said rod is moved in a direction toward the writing point end to effect a maximum ease of movement while maintaining a substantially airtight engagement with the bore of the barrel.

7. A fountain pen uf the character described including a barrel in which the bore at the `writing point end thereof is provided with means to break the vacuum created behind a plunger in its movement thereto for filling the barrel with a writing fluid, the plunger being mounted yon a rod for reciprocation in the barrel and comprising a yielding resilient rdisk having a central aperture, a backing plate on said rod having a face for engaging and supporting one side of said disk, and a clamping member of substantially smaller diameter than said disk for holding said disk in conforming engagement with said face of said backing plate and for permitting the periphery of said disk to stand spaced apart from the bore when the plunger rod is moved away from the writing point end, said clamping member being substantially rigid and having a reduced extension of substantially the thickness of said disk for passing through the aperture thereof and abutting against the backing plate -to prevent a substantial compression of said disk, the said face of said backing plate'terminating short of the periphery of said disk and presenting thereat a fulcrum for the flexure of the outer f portion of said disk on a substantial radius when said rod is moved in a direction toward the writing point end to effect a maximum ease of movement while maintaining a substantially air-tight engagement with the bore of the barrel.

8. A fountain pen of the character described including a barrel in which the bore at the writing point end thereof is provided with means to break the vacuum created behind a plunger in its movement thereto for filling the barrel with a writing fluid, the plunger being mounted on a rod forreciprocation in the .barrel and having a reduced connection at one end providing a shoulder, a plunger mounted on and secured to said connection, said plunger comprising a backing plate fitting over said extension and abutting said shoulder, a yielding resilient disk tting against one face of said backing plate and having a central aperture larger than said extension, and a clamping member engaging said connection on the other side of said disk from said backing plate to clamp said disk against the face of said backing` plate, said clamping member having a reduced extension passing through and fitting the aperture in said disk and being of a lengthto engage said backing plate when tightened thereby to prevent undue clamping pressure on said disk, the peripheral edge of said disk engaging the wall of the bore of said barrel, the clamping member being-of substantially Lsmaller diameter than said disk for holding said disk in conforming engagement with said face of said backing plate and for permitting the periphery of said disk to stand spaced apart from the bore when the plunger rod is moved away from the writing point end, said backing plate being substantially rigid and' extending over a substantial portion of said side of said disk to support the same, said backing plate being of such a diameter as'to present a peripheral fulcrum for the exure of the outer portion of said disk on a substantial radius when said rod is moved in a direction toward the writing point end to effect a maximum ease of movement while maintaining a substantially air-tight engagement with the bore of the barrel.

, W. A. SHEAFFER.. 

